Electrical reproducer for phonographs



Oct. 13, 1,557,529

E. T. JONES ELECTRICAL REPRQDUCER FOR PHONOGRAPHS Filed Dec. s, 1921 Horace;

PATENT. or-Flea.

EDWARD THOMAS J ONES, OF NEW ORLEANS, LOUISIANA.

ELECTRIC AL IRKPRODUCER FOR PHONOGRA IPHS.

Application filed December 3, 1921. Serial 1T0. 519,754.

To allwhom it may concern:

Be it known that I, EDWARD THOMAS JONES, a citizen of theUnited States, residing at New Orleans, in the parish of Orleans and State of Louisiana, have invented a certain new and useful Improvement in an Electrical Reproducer for Phonographs, of which the following is a specification.

.My invention relates broadly to phonographs and more particularly to an electrical reproducer for phonograph music.

The 0 ject of my invention isto provide an electrical device which is readily attachable to present forms of phonographs for the electrical reproductionof music at large volume for distribution over large areas which such as in auditoriums, ball rooms, amusementkplac'es and to out-of-door audiences.

. Another object of the invention is to provide-a telephonic reproducer'having standard parts assembled in such manner as to readily afford quantity production in manufacture. I

A further object of the invention is to provide means for amplifying the electrically reproduced music and controlling the volume of the sound. a

A still further object of the invention is to provide'an electrical reproducer adapted to conduct music direct to a pair of head telephone receivers to be worn by individuals in listening to the phonograph music.

' My invention will be more clearly under stood by reference to the following specification and the accompanying drawings in Figure 1 is a front elevation of the electrical reproducer mounted upon a disk phonograph; Fig. 2 is a side elevation of the electrical reproducer with its mounting partially in'section showing the means for securing the reproducer upon the phonograph; Fig. 3 is a diagrammatic view illustrating the electrical reproducer and its connections with a thermionic vacuum tube amplifying system; and Fig. 4 is a wiring -diagram s owing the electrical reproducer arranged for the reproduction of music through a air of head telephones to be worn b an individual.

: It Wlll be understood that the principles of my invention may be embodied in various forms and .that details are not material.

' The present embodimentof the invention,

, therefore, is to be considered as merely indicative. .The form illustrated in the drawing ing and hereinafter described in detail has been found to be one of the practical embodiments and capable of eflicient operation and practical in construction.

The electrical reproducer comprises a watch case telephone receiver construction mounted upon a swivel arm of the phonograph and having connections from the magnets within the receiver brought out to binding posts upon the casing thereof. The

diaphragm of the receiver is mechanically connected to the stylus of the phonograph and is arranged to be mechanically vibrated in accordance with the motion of the stylus over the phonograph record. The magnetic reluctance of the magnetic circuit within the receiver is thus varied 'in accordance with the musical vibration and electrical energy is proportionally generated in the" windings of the magnets. The magnets are electrically connected in an external re'pro: ducing circuit containing any desirednumberof stages of thermionic vacuum tube amplification having a sound reproducer connected in the. out-put circuit of the final stage of amplification. In some instances it is desirable to connect the magnets of the telephone receiver reproducer direct to a pair of reproducer telephones worn by the individual in listening to the phonograph music.

Referring more particularly to the drawings, Fig. 1 is a front elevation of the electrical reproducer for the phonograph repre-' sented by reference character 1. The phonograph is provided with a record table carrydisk record 2. A swivel arm 3 is mounted upon the cabinet'l and provides a support and guide for the electrical reproducer 5. The electrical reproducer 5 comprises a watch case type telephone receiver having supportin member 4, as shown in Fig. 2, secured to t e rearof the casing thereof provided with groove 6 adapted to cooperate with lugs 6 and 6 in the swivel arm 3 forming a rigid support for the electrical reproducer as it moves over the area of the phonograph disk. The watch case telephone re ceiver 5 contains a pair of magnets 12 having their windings 14 electrically connected to binding posts 7 on the casing of the receiver. These binding posts may include connecting lugs 8 whlch receive tips of a flexible cord connection to the reproducing circuit. The reproducer 5 is provided with diaphragm 10 which may be either mica or metallic construction. lVhen of mica construction a metallic armature'26 is carried by the diaphragm adjacent the poles of the magnets. The diaphragm is secured upon the reproducer 5 by means of ring 11 grooved at 13 to permit the lateral movement of lever 15 secured to the center of the diaphragm and pivoted at 16. The lever 15 is mounted to freely vibrate in pivot screws 17 and 18, rigidly secured by lock nuts 17 and 18 Within support 23, The support 23 is rigidly mounted upon the Watch case receiver 5 by means of supporting block 24 and screws 25.

The windings 14 of the magnets 12 are electrically connected as diagrammatically illustrated in Fig. 3 to the input circuit of a thermionic vacuum tube power amplifier. The amplifier may comprise vacuum tube 27 forming the first stage of amplification. The vacuum tube 27 includes a heated filamentary cathode 28, a grid 29 and an anode or plate 30. The plate is connected in the output circuit including the primary winding 33 of transformer 35 and battery 34. The filamentary cathode is heated by battery 32 and its incandescence regulated by rheostat 31. v The transformer 35 has its secondary winding 36' connected to the input circuit of a second stage of amplification comprising vacuum tube 37 having the heated filamen tary cathode 39, grid 38 and plate 40. The filamentary cathode is heated by battery 42 and its temperature regulated through rheostat 41. The plate is connectgd to the output circuit including the loud speaker reproducer 43 and battery 44. The loud speaker reproducer 43 has its field windings energized by battery 46 and is provided w th a sound conveying horn for directingthe music to any desired area.

The power amplifier as above descrlbed is adapted to increase the volume of reproduced music to any desired degree. By reason of the electrical characteristics of the thermionic vacuum tubes there is no distortion of the music and the intensity of the music is under control of the operator by regulation and adjustment of the filament rheostats 31 and 41. i Fig. 4 is a wiring diagram of a system for the individual reproduction of music in head telephones 48 electrically connected through a flexible cord to terminals 47 which in turn connect to terminals 7 of the electrical reproducer 5.

In the operation of this reproducer the phonograph record is set in motion and the electrical reprbducer 5 brought into position over the record so that stylus point 22 is vibrated in accordance with the form of the record grooves which mechanically imparts vibrations to the diaphragm 10 which vary the magnetic reluctance of the magnetic circuit through the magnetic poles of the. watch case telephone receiver. This variation of magnetic reluctance through the magnet poles generates minute currents 1. A phonograph reproducer comprising a watch case telephone receiver having a pair of magnets, a diaphragm adjacent the poles thereof, a screw threaded ring for securing said diaphragm in position, a support secured on the exterior of said watch case adjacent said magnets, a stylus arm formed of a single piece of material pivotally mounted in said support and provided at one end on one side of said pivotal mounting with astylus point and secured at the other end on the opposite side of said pivotal mounting to' said diaphragm and electrical connections from said magnets to a reproducing circuit.

2. In a phonograph, the combination with a. record of an electrical reproducer comprising a watch case telephone receiver having a shell casing, a pair of magnets therein, a diaphragm adjacent the poles thereof, a screw threaded rim having a cut away portion at one side thereof, a yoke member secured to said casing adjacent said magnets and extending over said rim, said yoke carrying a air of pivot members extending toward eac other, a stylus lever formed of a single piece of material pivotally mounted in said yoke and attached to said dia-' phragm and arranged for lateral movement in said cut away portion of said rim whereby said diaphragm is mechanically vibrated by said record to corres ondingly vary the magnetic reluctance of t e magnetic circuit within said telephone receiver and means for observing said variations. 1

3. In a phonograph, the combination with a tone arm and record of a reproducer comprising a watch case telephone receiver including a casing, apair of magnets, a diaphragm adjacent the poles thereof, a screw threaded ring for securing said diaphragm in position, a member secured .to

the rearof said casing on the axis thereof for attachment with said tone arm, a stylus point adapted to be mechanically actuated by said record and means for imparting corresponding vibrations to said diaphragm,

said magnets being electrically connected to a reproducing circuit.

4. In a phonograph, the combination with pair of magnets therein, a. diaphragm and' an armature carried by said casing adjacent the poles of said magnets, a screw threaded ring for securing said diaphragm in position on said casing, a support secured to the center of the exterior wall of said casing, a grooved connection between said supportand said tone arm, a pair of plugson said tone arm for locking said watch case telephone receiver in position on said tone arm, a stylus arm consisting of a single piece of material pivotally mounted on said casing and provided at one end with a stylus point and secured at the opposite end to said diaphragm and electrical connections from said-magnets to a reproducing circuit.

5. Ina phonograph, the combination with I a, record, and an electrical reproducer com- I prising a watch case telephone receiver hav= mg a shell casing, a pair of magnets therein, a diaphragm adjacent the poles thereof, a screw threaded rim for securing said diaphragm inposit-ion, a spacing member at-.

tached to the exterior wall of said shell casing'adjacent said magnets, a yoke mounted on said spacing mem er, a pair of diamete. rically opposed bearings carried by said yoke, a stylus lever pivotallymounted in said bearings, a stylus point at one end of said lever adapted to engage said record, a connection between said diaphragm and the opposite end of said lever whereby to vary the magnetic reluctance of the magnetic cir- .cuit within said receiver in accordance with mechanical vibrations of said stylus.

EDWARD THOMAS JONES. 

